Air-brake system.



E. G. TA,YLOR.

AIR BRAKE S/STEM.

APPLICATION FILE-D JAN. 13, 1917.

Patente Feb. 25, 1919.

4 SHEETSSHEEI l.

INVENTOR WITNESSES E. G. TAYLOR.

AIR BRAKE SYSTEM.

APPLICATl ON FILED JAN. 13. 1917.

Patenred Feb. 25, 1919.

4 SHEETSSHEE[ 2.

E. G. TAYLOR. AIR BRAKE SYSTEM.

APPLICATION EILED JAILJ3. I917.

Paten Feb. 25., 1919.

4 SHEETSSHEE[ 4.

55-? VICE LA P FIGJB3 INVENTGR 45 by pmnp 2;

EARL (z TAYLOR, OF BELLEVUE, PENNSYLVNIA.

FAIR-BRAKE SYSTEM.

Specificacion of Letters Patent.

Patented Feb. 25, 1919.

Application filed Janury 13, 1917. Srial No. 142,148.

T u.Zl a s/10m. it may concern:

Be it known that I, EARnG. TAYLOR, a resident of Bellevue, in the county of Alleghcn y and State of Pennsylvania, have invented a new and useful Improvement in Air-Brake Systems, of which the following is a specification.

The invention relates to air brake systems in whivh the engine and tender brakes are (ontrolled indepehdently of the car brakcs,

- and the object is to provide an improved system of' this kind in which the independent control above namcd is secured auto matiCally by the n'ianipulation of a single operating handle.

the automatic control valve; Figs. 3 and 4 are. transversesections thrugh said' valve taken respectively on the lines and 44, Fig. 2; Fig. 5 is a vertical section through the engineers valve;Fig. 6 is a plan view of the valve seat.member of the engineers valve and showing the connections of the piping thereto; Fig. 7is a plan view of the valve seat on an enlarged scale; Fig. 8 is a plan view qf the rotary member of said valve; and Figs.,9 to 16 inclusive are plan views of the Valve seat with the rotary mcmber.on top thereof and showing in dotted lines the Connections made in the difcrent positions of the rotary, Fig. 9

sh wing the same in running position, Fig.

10 in service position, Fig. 11 in service lap pos1t1on, Fig. 12 in independent engme relt zase position, F 1g. 13 n emergencv apphat1on position, Fig. 11 in stra1ght a1r eng1ne brake application position, Fig. 15 in straight air lap position, and Fig. 16 in engine brake full release position.

The s ystem illustrated includes a main reservoir 1, supplied with compressed air an engincers control valve 3; a train pipe 4 having connected thereto, through brunch pipe 19, the usual car brake equipmcnt comprising a brake cylirider 16, anxiliary reservoir 17, and triple valve 18;

an automatic control valve 5 connected throngh pipe 15 to the engine and tender 1 rake c vhnders 6, 6 and 7; and pipi g; conncuting the'se parts, to-W1t, a pipe 3 connerting the main rescrvoir to the engincers brake valve, through a feed valve 9 which may be of any suitable type; a pipe 10 connecting the main reservoir to the automatic contre] valve 5; a pipe 11 connecting the enginecrs brake valve 3 with the train pipe 4 and having a branch 14 cOnnecting to the automatic control valve 5; a pipe 12 Conmeeting the engineers brake valve to the automatic Control valve 5 for applying the engine brakes directly; and a pipe 13 also nnnecting the engineers brake valve With the automatic control valve for holding the engine brake supplied When the train brakes are released.

The automatic control valve 5, shown in Figs. 2, 3 and 4, is so arranged that by proper manipulation of the engineers brake valve the engine brakes and car brakes can be applied and released independently, or

'can be applied simultaneously and either the car brakes or the engine brakes held while the other is released. This valve is provided With a housing 20 in which are 'located two movable abutments 21 and 22 operating in chambers 23 and 24. Each abutment is provided with suitable packing 25, as shown.

The abutment 21 is operated by train pipe pressure which is admitted to the upper portion of the chamber 23 throgh the opening 26 to Which the pipe 14 is connected. This abu tment is consequcntly responsive to variations in train pipe pressure and. moves in response to variations made for the purpose of operating the car brakes.

The second abutment 22 which controls the engine brake cylinders directly is controlled in part by the nwvement of the first abutment, that is, whenever it is desired to apply orreleasethe car and the engine brakes simultaneously, ait is relased or admitted to the control valve 5 so that the movement of the abutment 21 causes the abutment 22 to move to apply or release the engine brakcs.

The abutment 22 carries a stem 27 which engages the stem 28 of a check valve 29 controlling communication between a chamber 30 to which the pip L0communicating with the main reservoir -is connected, and a ch an1ler 31 to Which the pipe 15 com nmmcaung with the engine brake cylinderis connected.- 'lhe check valve 29 is nor- 1nally closed by gravity and main raser above and 1oe1ow the abutment and in the pressure retaining tank 76 are equa1i2ed, the check valve42 is closed by a spring 43 and the pressure is trapped in the retaining tank for use in operating the abutment 22,

valve 'is arranged so that when the control,

handle is placed in the proper position to increase the train pipe pressure, pressure is admitted through the pipe 13 to the chamber at the l0wer end 015 the automatie control valve and below the check valve The pressure admitted through this pipe is main reservoir pressure whioh is greater than train pipe pressure and which therefore li0lds the check valve against its seat preventing the pressure from beneath the abutment 22 from bcing vented t0 atmosphere through port 54, even though the abutmemt 21 moves the check valve 19 off its seat in moving downward1y undcr increase in train pipe pressure lo release the car brakes. Consequenfly, the abat-ment 22 W111 not move and the engine brakcs W111 romain app1ied While the car brakes are being relcased when pressure is admittcd to pipe 13.

It is also deslrable to control the engine l rakes independently of the car brakes, and for this purpose the pipe 12 from the engineers eontrol valve is comieeted to the autonmtic valve so that it commvnicates with the passage 70 and the lower side of abutment The engineers valve is arrangcd to admit or exhaust pressure through the pipe 12 and thereby move the abutment 22 up or doWn to apply or reiease the engine brakes. '1he admission of pressure to the pipe 12 contro1led by the engineers valve in such a way that the car brakes are 11013 operated when the engine brakes are being operated by straight air by the admission and release of air through the pipe 12.

T 11e ongineers brake valve comprises a suitable housing and a base member 84, betWeen which is interposcd the stationary valve seat member 81, and a rotary member 82 controlled l y handle 83 ha ing the usual spring pressed pawl engaging notches in a segnnmt on the housing. Main reserv0ir pipe 8 connnlinieates with a chamber 85 in the valve housing above the rotary 82 through a passage 87 extcnding through -the member 81 and which oommunicatcs hrougb a branchpawage 88 leading to a port in the valve sea: and also arranged to be connected to a pipe or passge leading to the feed valve 0, not shoxvn the return from said feed valve be1ng through the passage 89 the valve housing to a port in the valxe seat. Tire pipe 11 communicating with the. train pipe is connected as shown in Figs and 6 With pasm Fig. 5,

sage leading to a port in the valve seat. The pipes 12 and 13 are also connected so as t eommunicate With ports in said valve scat. The housing also has an exhast passage 90 Which registes With a corresponding passage in the valve seat.

The valve seat 81 is provided With seven ports and passages, as foll0wsz A thr0ugh port 91 communicating With the passage 88 in the valve housing leadinp to the main reservoir; a through port 02 communicating with the passage 80 from the feed valve; a'through port 93 communieat' ing with the train pipe through the pipe 11; a through port 94 communicang with the pipe 13 leading to the automatic control valve 5 for purpose of holding the engine brakes applied While the car brakes are released; a recess port 95 having a small extension 01 1 to the port and recess communicating by a eored-out passage 97 with.an exhaust passage 08 which registers With the exhaust passage 00 in the main housing; a thr0ugh port 99 communicating with the pipe 12 leading to the automatio contro1 valve 5 for the purpose 01 independently controlling the engine bralccs, said port also connnunicang with a recessed passage 100 in the topface of the valve seat; and a recess 101- communicating with the exhaust port 98.

The rotary me1nber shown in Fig. 8 is providcd on the face Which coperates witl1 the valve scat with a reccss 102 adapted in var1ous positions of the rotary to estal lish difierent communications l etween the ports 91, 02, 02') and 95 of the valve seat. This recess hasa small extension 103 which cooperats with the port 00 in the valve scat in certain positions of t1re rotary. The rotary has another reccss 103 in its face which coperates With the reeesses 100 and 101 in the valve seat. The rotary is also provided with a rece ss 105 on its nnder face which registers in certain positions of the rotary with the port .04: in the valve seat and which communicates at :111 times With the exhaust passage 98 in the valve seat. The rotary also has a through port 107 WhiCh 006perates With the port 04 in the valve seat; and a thrk ugh port 108 which coperates With the recess 100 in the valve seat.

The rotary has eight positions relative to the valve seat, as follm vs This position is shown in Fig. 9. The reccss 102 establishes comnmnication loctween the port 92 from the fecd valve and the port 03 leading to the train pipe, and the train pipe is accordingly Charged from the main reservmrthwugh the fend valve. T110 recess 101 also conneecs recess 100 and its port 99 with the recess 101 lea ling to exhaust, there by ventmg the. pressure in pipe 12 to atmosphere and permitting the abutment 22 in the automatic control valve 5 to move downwardly and vent the engine brake cylirrders to release them. In this position the engine brake cylinders are released by being vented to atmosphere and the train pipe is in communication with the main reservoir through the feed valve so that the car brakes are releascd. The recess 105 registers with the port 94 and thereby establishes communication between the port 94 and atmosphere through the exhaust passage 97. This insures that in running position there Will be no pressure in pipe 13 and below the check valve 52 in the automatic control valve 5, which pressure might prevent the venting of the pressure from beneath the abutment 22 for releasing the engine brakes.

2. Service position.

In this position, which is shown in Fig. 10. the rotary has been moved farther in a counter-cloclnviSe direction, breaking comnnmicating between the port 92 from the foed valve and the port 93 to the train pipe and stablishing communication between the port 93 and the narrow portion 96 of recess 95 which in turn communicates with the ex haust port 98 through the passage 97. The train pipe is accordingly vcnted t0 atmos- ,phere through a relatively small passage.

'between the main reservoir and the engine brake cylinders to apply the engine brakes.

3. Service lap position. In this position, shown in Fig. 11, the

' rotary has been moved back a short distance in a clockwise direction from the position shown in Fig. 10 and all the ports are blanked. T he rotary is generally moved to this position after it has been moved to service position and the blanking of the ports leaves the brakes applied to a degree corresponding to the length of time the rotary has been left in service position.

4;. lndepondent angine release position.

The rotary is moved to this position, shown in Fig. 12, When it is desired to release the engine brakes independently of the car brakes. The rotary is moved clockwise a slight distance from the service lap posi tion shown in Fig. 11. In this position all the ports leading to the train pipe are blanked and the car brakes remain applied but the recess 104 registers With t e recesses 100 and 101 and thereby establishes communication between the port 99 and the atmosphere. This exhausts pressure thrOugh the pipe 12 from the lower side of the abutment in the control valve 5, causing said abutment to be moved downwardly to open 5. Emcrgcnoy position.

This position, shown in Fig. 13, is obtained whenit is desired to secure a sudden or emergency application of the brakes. The rotary is moved counter-cloclmise beyond the service position shown in Fig. 10. In this position the recess 102 establishes full communication between the port leading to the train pipe and the port, 95 to the atmosphere so that the train pipe vented rapidly to the atmosphere to cause the triple valves on the car brakes to go to emergency position and give an emergency application of the brakes. The through port 108 also registers in this position with the port 99 in the valve scat, thereb admitting main reservoir pressure from the top of the rotary through the port 99 to the pipe 12 and the lower side of the abutment 22 in the automatic control valve which moves said abutment upwardly rapidly and causes the main reservoir pressure to fiow to the engine brake cylinders to apply the engine brakes.

6. Stmight air application position.

The rotary is moved to this position, shown in Fig. 14, when it is desired'to apply the engine brakes independehtly of the car brakes. The rotary is mOved from running position shown in Fig. 9. sition the extension 103 of the recess 102 in the rotary registers With the port 99 in the valve scat and establishes communication between said port and the port from the teed valve and main reservoir. This permits pressure to fiow throngh the pipe 12 to the lower sideof the abutmcnt 22 in the control. valve 5 which moves the abutment upwardly and unseats the check valve 29, permitting main reservoit pressure to fiow to the engine brake cylinders to apply the engine brakes. The recess 102 also es tablishes communication between the port 92 from the feed valve and main reservoir and the port 93 lea ling to the train pipe, thereby maintaining pressure in the train pipe and kceping the car brakes rcleased. The. pressure below abutment 22 communicates through passage 55 with the lower face of check valve 49 and maintains said valve clo ed, thereby preventing the pressure be In this po 10W abutment 22 being vented t0 atmosphere because of maintenance of brake-pipe pressure.

7. .8tmgfit air Za;p position; shown in Fig. 15.

the rotary a short distance counter-clock- Wise from the positionshown in Fig. 14. In this position the communication between port 99and recess 103 is broken and the air below the abutment 22 in the control valve is trapped. The recess 102 maintains com municatirin between the port 92 from the feed valve.and the main reservoir and the port 13 leading to the train pipe so that pressure is maintained in the train pipe and the car bral tes remain released. The port 107 also reg1sters in this position With the port 94 and admits main reservoir pressure from the top ofthe rotary to the pipe 13 and behind the check valve 52, thereby preventing pressure being vented to atmosphere through port 54 from below the movable abutment 2.2. Vhen a service application has been made and it is desired to release the car brakes and hold the engine brakes applied, the valve is moved to, straight air lap position which admitS pressure to the train pipe to release the car brakes, but holds the engine brales applied as above explained.

8. Full rclease position shown in F zg. J6.

93 leading to the train pipe. Main reservoir pressure is therefore admitted to the train pipe without being reduced by the feed v tainin}; the engine brakes applied.

valve, as is the case in all other positions of.

the valve. Tliis fully releases the car brales, as Will be readily underst0od and at the same time releases the engine braLkes tlirough the automatic control valve 5.

This apparatus giVes the engineer complete and independent control of the engine and'the train brakes by means of one engi neers brake valve. It is merel necessary to' move the control lever of said valve to the required position for either applving the ei1gine brakes separately or applying 'them simultaneously -with the train brakes or for releasing the train brakes and main- The oontrol valve 5 opelates automatically. is simple in construction and rcqires vcry little attention. The entire apparatus is relativelv simple and may be inexpensively Jnanufactured. v

One of the important advantages of the control valve is the'automatic pressure maintaining feature. After the abutment 22 is operated, either independently or with the train brakes to apply the engine brakes and the handle of the engineers valve is placed in one of the lap positions. the abutment 22 Will automatically maintain the engine brake cylinder pressure, if such pressure is reduced for any reason as by a leak in any of the connections or in the brake cylinder. Any reduction in brake cylinder pressure Will reduce the pressure, the chamber above the abutment 22 through groove 56 and said abutment Will be moved upwardly by the pressure under it, thereby again admitting pressure to the engine brake eylinders to raise the pressure to the required amount.

This is an important advantage because it frequently happens that leaks occur Which cause the brakes to be gradually relcased after they have been applied.

This apparatus is also-particularly advantageous when used With two engines which are coupled together for double heading purposes. In such cases it is desirable to have all the brakes controlled by one engineer, preferably the engineer of the first en gine. In the apparatusherein described, the cnginers brake valve on the second engine is placed in service lap position in which all the ports of the valve are blanked. W'ith the engineers valve on the second engine in tliis position, the automatic control Valve on the second engine is nevertheless responsive to variations in train pipe pressure and consequently the engineer on the first engine has control of the brakes on the second engine in the same way that he has control of the car brakes. In other words, the automatic control valve on the second engine acte similarly to a triple valve.

If the ngineer on the, second engine should desire to release the engine brakes on his engine independently of the first engine or the train, he can do so by placing the handle of the engineers brake valve in independent engine release position Which will release his brakes but not afiectthe first engine or the train.

Also, if it is desired to have the engineer on the second engine assist in releasing the train and holding his enginebrakes applied, this can be done by placing his engineers brake valve in straight air lap position.

These advantages in the use of the apparatus for double heading Will be readily appreciated since these functions can be secured without any-auxiliary adjustment of the equipment and at the same time every requircmcnt of braking; service is madc.

It is to be understood that the structures 10Wn are for purposes of illustration and Lnat other structures may be devised which oome Within the spirit and scope of the ap pended elaims.

lVhat I claim is:

1. The combination in an air braks system having a main reservoir, train pipe, engine and car brake oylinders, of an auto matic eontrol valve, and an engineers valve perable by a single handle, said oontrol valve having a nmvable abutment arranged to control the supply and exhaust of motive fluid to and from the engine brake cylinders, a second movable abutment responsive te variations in train pipe pressure arranged when moved by inereases in train pipe pres sure to exhaust motive fluid from one side of the first abutment and when moved by deereas s in train pipe pressure to admit motive fluid to the said Side of the first abatment, and means rendered operable by the admission of pressure thereto when the engineers brake valve is moved tonne position to inerease the train pipe pressure for ;revent ing the exhaust of pressure rom said side of the first abutment by the movement of the second'abutment under the increase in train pipe pressure.

The combination in an air brake system having a main reservoir, em rineers valve, trainpipe, angine and car brake cyl inders, of an autonmtic eontrol valve havin an abutment controlling the supply and exhaust o:f fluid pressure to and from the engine brake eylinders, a second abutment responsive to variations in train pipe pressure and arranged to control the supply and exhaust of fluid pressure to and from one side of the first abutment whereby when the seeond abutment is moved in response te variations in train pipe pressure in the application and release of the car brakes, the seqond abutment moved to sinmltaneously apply and release the engine brakes, said automatic eontrol valve bei1'}g provided with means for preventing the movement of the second abutment When the first abutment is an'automatio contre] valve having an abut ment controlling the supply and exhaust of fluid pressure to and from the engine brake 'eylinders, a second abutmei1tresponsii te variations in train pipe pressure and arranged to control the supply and exhaust of fluid pr ssure to and from one side of the first al u nient, whereby when the second abutn.ent

is moved in response to variations in train pipe pressure in the a 1pplicationand release of the"car brakes, the second abutment is the car brakes, wlnerehy brakes may be held applxed Wliw; marln'akes are released, sa1d eontrol valu liaV1ng 1neans arrangedso that [laid n ;me may l e admitted to the lirst almlmeni ia'liile the train pipe pressure is nn C tain the car l rakes;; l'tldihi pressure .is admitted to the en;:eru l r::l ;e eylinders to independentiy :ippl lie engine brakes.

4. The combination in an air bral;e system liaving the main rese1v(iir, train pipe, engine and ea1"brake eylimlers, et an auto- 1natie eontrol valve and an engineers valve operablebyagi1iglehandle. said eontrol valve having a movable abutment arranged when 1 noVed b v increases in train pipe pressure to exhaust motive fluid from one side of the first abutment and when 1noved l y lectrreases in train pipe pressure to admit motive fluid to the said side of the first abutment, means rendered (meralile l)} the admission of pressure thereto \\lien the engineefls lnalie valve is moved to one position lo inere;mthe train pipe pressure for preveniin;r the eKlzaust of pressure l"rom one side et the first almlment by the movement of the second al1utment under the inerease in train pipe pres sure. and means arrahged se tlxat* When tlie engineeNs l1rake valve is moved to anotlier position (laid pressure is admitted dirt.etlv to one side et the iirst abutment io move the saine to admit pressure to the engine brake eylinders while train pipe pressure romains constant.

5. The combination with an air lnake systein lxaving a main reservdir, i'eed valve, train pipe, engine and car bral e evlimlers,- of an automatic eontrol valve having an abutment arranged to control l'lit simplv of feed eontrolled pressure to the engine l1ralfl: e vlinders and the exhaust I'rom said cylinders, a seeond al utment responsive to variations in train pipe pressure and arranged le control the supply and exlmusi o fluid pressure to and from the lirst aliutm nh said en gineefis l;rake valve hein}; arran;jed so tlxat wvhen in position to inerease the train pipe pressure to.releasethe car brakes,lhe seeond anutment 1s moved wlneh causes the lirst 'ahutment io be moved to exhausipressure opposite direction to admit feed eontrol pressure in the engine brakecflinders, said engmeers valve belngalso arranged so that when moved to another position for increas- 1ng the tram pipe pressure to release the car brakes, pressure 1s adnntted to means in the auton1atic control valve for:preventing the movement of the second abutment under the increase in train pipe pressure for movingof feed eontrolled pressure to the engine brake cylinders and the exhaust from said cylinders, a second abutment responsive to variations in train pipe pressure and arranged to control the supply and exhaust of fluid pressure to and from the first abritment, said engineers brake Valve being arranged so that when in one position to increase the train pipe pressnre to release the car brakes, the second abntment is moved which causes the first abutment to be moved to exhaust pressure from the engine brake cylinders, and When moved to another position to decrease the train pipe pressure to apply the car brakes, the sec ond abntment is moved in an opposite direction to cause the first abutment to be moved in the opposite direction to admit feed valve pressure to the engine brake eylinders, said engineers valve being'also arranged so that when moved to another position to in0rease the train pipe pressure t0 release the car brakes, pressure is admitted to means in the automatie control valve for preventing the movement of the second abutment under the increase in train pipe pressure for moving the first abutment, Whereby the engine brakes remain applied, said engineefis v'alve being further arranged so that when moved in another position with the train pipe pressure exhausted, main reservoir pressure is admitted directly to one side of the first abutment to operate it to admit pressure to the engine brake cylinders While the car braks remain released.

7. An automatic oo ntrol brake systems having a movable abutment arranged to control the supply and exhaust of fluid pressure to a brake cylinder pas: sage, a second abutment controlling the supply and exhaust of motive fiuid to one side of the first abutment, said first abutment being arranged to automatidally maintain the pressure in the brake cylinder pas sage constant When the valve meehanism is in position to maintain pressure in such passage.

8. An autoxnatie control valve for air brake Systems having two movable abut mente, one of said abutments being arranged when mgved in one direction to admit fluid pressure t0 a brake cylinder-passage and valve for air 3 When moved in the opposite direction to open a vent from said passage te atmosphere, the other of said abutments bing responsive t0 train pipe pressure and being arranged when moved by increases in train pipe pressure to vent pressure from one site of the first abutment to cause said first abutment to be moved to vent the brake cylinder passage, said second. abutment aise being arranged so that When moved by de creases in train pipe pressure it admits pressure to one side of the first abutment to move said abntment t0 admit fiuid pres sure to the brake oylinder passage.

9. An automatic control valve for air brake systems having tWo movable abutments, one of said abutrnents being arranged when moved in one direction to admit fluid pressure to a brake cylinder passage and when moved in the opposite direction to open a vent from said passage to atmosphere, the other of said abutments being responsive to train pipe pressure and being arranged when moved byincreases in train pipe pressure to vent pressure from one side of the first abutment to cause said first abutment to be moved to Yen-t the brake cylinder passage, said Second alentment also being arranged so that when moved by decreases in train pipe pressure it admits pressure to one side of the first abutment. to move said abutment to admit fiuid pressure to the brake e}ylinder passage, and means for preventing the second abut ment from venting pressure from below the first abutment under .predetermined conditions.

10. An automatic control valve for air brake systems having a movable abutment controlling the admission and exhaust of fluid pressure t0 a brake cylinder passage, and a; second abutment responsive to train pipe pressure and arranged to control the admission and exhaust of fiuid pressure to one side of the first abutment whereby when the train pipe pressure is increased the second abutment is moved to vent;pressu.re from one side of the first abutment t0 cause it to be moved to vent the brake Cylinder passage and When the second abutment is moved by decreases in train pipe pressure, pressure is admitted to one side of the first abutment to more it to admit pressure to the brake eylinder passage.

11; An automatie oontrol valve for air side of the first al utment so that it is moved to vent the hrake cylinder passage, and when the second abutment is moved by decreases in train pipe pressure. pressure is admitted to the same side of the first abutment to move it to admit pressure to the brake cylinder passage, and means for preventing the n10Ve1nent of the second abutment under decreases in trainpipe pros sure ior ventinp; the pressure from one side of the Iirst abutmenc.

12. An automatie control valve for air brake svstems having a movable abutment controlling tlie supplg and exhaust of 1110- ive fluid to and irom a brake cylinder pas sage, a second movable abutment responsive to variations in train pipe pressure and al ranged 120 control the supply and exhaust of motive fluid 110 and from one side of the first abutment, whereby when the second al utn1nt inoved by increases in train pipe pressure, the first abutment moved to ex l1aust pressure from the brake cylindcr passage and wlien the second abutment is moved by decieases in train pipe pressure the first almtment is moved to admit pressure to the ln-ake cylinder passage, and means for admittin;r pressure to one side of the first abut ment imlependcntly of the second abutment to thercby cause said abutment to be moved to admit pressure to the brake cylinder pas sage.

13. An automatie control valve having a movaole abutment eontrolling the supply and exhaust of fluid pressure to a brake cylinder passage, a second mOvable abutment responsive.to variations in train pipe pressure and controlling the suppiy and exhaust of' fluid pressure to and from one si de of the first alnflzment so that when the second alentment is moved by increases in train pipe pressure, the first abutment is moved to exhaust pressure from the brake cylinder pas sage, and when the second abutment is moved by decreaSes in train pipe pressure, the first abutment is moved to admit pressure to the brake cylin der passage, means operable under predetermined conditions to prevent the first abutment bein'g movcd when. the second is moved under increases in train pipe pressure, and means for admitting, pressure to one side of the first abutnnt to move the same independently of the second abutment t0 cause pressure to be admitted 130 the brake cylinder passage while the first abument and the train pipe pressure romains constant.

14.. An automate eontrol valve for an air Xbrake system having two movable abutments,

ment being arranged when moved in one direction to open 'said check valve and admit pressure.to the brake eyhnder passage, a

ond check valve controlling a vent from the brake cylindcr passage and arranged to be operated by said first abutment when it is moved in the opposite direction, a third check valve controlling a vent from one side of the first abutment t0 atmosphere and be in; arranged to bemoved by the second abutment when it is m0ved in one direction to thereby vent pressure from one side of the second abutment and permit said abut ment to vent pressure from the brake cylinder passage, and a fourth check valve con trolling a passage from a fluid pressure suppl v to one'side of' the first abutnient, said fonrth check valve hein arranged to be operated by the second abutment when it is nmved in the opposite direction to thereby admit pressure to one side of the first abut ment-t0 move it to open. the first check valve and admit pressure to the brake cylinder passage.

15. An a-utomatie control valve having a movable abutn1ent controlling the supply and exhaust of fluid pressure to and from a. brake eylinder passage, a second movable abutment responsive t0 variations in train pipe pressure and arranged to control the supply and exhaust of motive fluid to and from one side of the first abutment so that when the second abutment is moved nder increascs in train pipe pressure, the first abutment is moved to vent pressure from the brake cylinder passage, and when the second abutment is moved under decreases in train pipe pressure, the first abutmemt 1noved to admit pressure to the brake cylinder passage, the opposite side of the first almtmemt. being: in restricted communication. with the brake cylinder passage, whereby when undesited reduotion in pres sure takes place in the brake cylinder pas sage, the first abutment is automaticaIly moved to admit fluid pressure to the brake eylinder passage to maintain the pressure at the required amount.

16. Tire combination of an air brake systen1 having the usual main reservoir, train pipe, angine and car brake cylinders, of an engineers brake valve and an aulomatic control valve for co:rtroHingthe fluid pressure to the engine brakecylnders, said c0ntrol valve being responsive to train pipe pressure whereby when the engineers brake valve is laced in a certain position the engine brakes may be controlled by variations in train pipe pressure from another point, said control valve and engineers valve being also-a1ranged so that the engine brakes may be released independently of the train pipe pressure.

17. The combination with an air brake system, of an automatic control valve responsive to variations in train pipe pressure for controlling the fiow of fluid pressure to the engine brake eylinders, and an engneers valve for controlling the floW of ressure tuated ndependehy of the train pipe to the automatic control valve and t e train pressure. 10 pipe, said engineers valve being arranged 50 In testimony whereof, I have hereunto set that in one position 2L1] ports are blanked my hand.

and the automatic control VLIVe s responsive EARL G. TAYLOR.

4to variations in train pipe pressure and also Witnesses:

being arranged so that when moved to an- G. H. LERESCHE, other'position, the control valve. may be 30- R. W. EMER.- 

